For example, contents such as a movie or music are provided to users through various media such as a digital versatile disc (DVD), a Blu-ray Disc (registered trademark), or a flash memory, a network such as the Internet, or a broadcast wave. Users can reproduce contents using various information processing devices, for example, a PC, a portable terminal, a recording and reproducing device such as a BD player, and a television.
However, copyrights, distribution rights, and the like of many contents such as music data or image data which are provided to users are possessed by the creators or sellers thereof. Therefore, content providers often performs predetermined content usage control when providing the contents to users.
According to a digital recording device and a recording medium, it is possible to repeatedly record and reproduce, for example, an image or audio without degradation, and thus there is a problem in that the delivery of illegally copied contents through the Internet and the use of illegally copied contents such as the distribution of a so-called pirated disc have become pervasive.
Encryption processing of contents is an example of a specific configuration for preventing such unauthorized use of contents. The configuration is set such that a content to be provided to a user is encrypted to allow only an authorized user to acquire the encryption key thereof. These pieces of processing are disclosed in, for example, PTL 1 (Japanese Unexamined Patent Application Publication No. 2008-98765) and the like.
An encryption key which is used to decrypt encrypted data is recorded together with an encrypted content in a user's medium, for example, a memory card, at the time of purchasing, for example, downloading the encrypted content.
At the time of reproducing a content, a reproducing device equipped with a memory card reads out an encrypted content and an encryption key from the memory card, decrypts the encrypted content by applying the encryption key, thereby allowing the content to be reproduced.
In this manner, the encrypted content and the encryption key are recorded as one data set in a medium such as a memory card, and thus a so-called medium binding type content usage control of associating a content with one medium is realized.
Such a medium binding type content can be reproduced in various reproducing devices on which a medium can be mounted.
Many of current content acquisition processes are performed by content downloading processing through a network. Users store a downloaded content in a medium such as a memory card and mount the medium on various reproducing devices to read out the content from the medium and reproduce the content.
However, there is a possibility of the medium storing the content being damaged or a possibility of a user erroneously deleting the content from the medium.
In order to respond to such a problem, content distribution service providers such as a content provider have taken the following responses, for example.
(a) A content is allowed to be downloaded to a plurality of media.
(b) A content is allowed to be downloaded again in response to a request that a user has damaged a content storing medium or has erroneously deleted a content.
For example, user convenience is improved by taking the above-described responses.
However, in reality, a request indicating damage of a medium or erroneous deletion of a content is not always made correctly, and there is a possibility of the request being a false request.
Therefore, while downloading to a plurality of media and re-downloading improve user convenience, this downloading also becomes a factor that increases unauthorized use and distribution of a content.
There is a possibility of an unauthorized user making a request indicating damage of a medium, in spite of the medium not being damaged, to illegally download a content, to record the content in a plurality of media, and to assign or resell the media to other people.
When such processing is performed, unauthorized use of a content becomes pervasive.
As a configuration for preventing such unauthorized use, the following content usage control is also suggested and is implemented in some parts.
That is, a user's reproducing device is connected to a content management server before reproducing a content, and user account information such as a user ID is transmitted to a server. The server confirms that a user account is an account of a legally-registered user, and transmits content reproduction permission to the reproducing device on condition that the confirmation is made. The user's reproducing device starts content reproduction on condition that reproduction permission information is received from the server.
A system performs such a control.
However, in order to perform the above-described control, the user reproducing device has a communication function for communicating with the server and is required to be installed in an environment where communication can be performed.
Therefore, for example, in a reproducing device or car navigation system with no communication function, or in an environment where communication cannot be performed such as the inside of an airplane, reproduction permission information cannot be received from a server, and thus a content cannot be reproduced.
In addition, there may be a problem in that a content cannot be reproduced even during a period when a server stops operating due to, for example, the failure or maintenance of the server.